A way of measuring rotational speeds and accelerations is, for example, using micro-mechanical gyroscopes, i.e. rotational rate sensors. These rotational rate sensors may exemplarily make use of the Coriolis force to find out a rotational speed or acceleration. In conventional rotational rate sensors, micro-mechanical resonators are, for example, put in controlled oscillation for this purpose which is also referred to as excitation oscillation. The oscillating structure formed in this way additionally comprises another resonant mode which is coupled to the excited mode, for example proportional to the Coriolis force and thus the rotational rate. The result is the possibility of utilizing an oscillation of the second resonant mode which is also referred to as detection oscillation for measuring the rotational rate.
In conventional technology, sigma-delta modulators are used for measuring the rotational rate, i.e., for example, for detecting the amplitudes of excitation and detection oscillations, the noise suppression characteristic of which can be adjusted such that they achieve the best quantizing noise suppression possible in the excitation frequency. Deviations occurring between the frequency of the maximum attenuation of the sigma-delta noise transfer function and the true oscillation frequency may result in a deterioration in the system performance due to increased noise in the signal band which cannot be attenuated or suppressed, not even by filtering.